Tip for ultrasonic dental instrument

ABSTRACT

AN ULTRASONIC DENTAL INSTRUMENT WITH A CHUCK FOR QUICKLY ATTACHING AND DETACHING A WORK TOOL WHICH CHUCK REQUIRES THE USE OF NO SPECIAL TOOLS. A CONVENTIONAL MAGNETOSTRICTIVE ACOUSTIC TRANSFORMER IS INCLUDED IN THE DENTAL INSTRUMENT TO VIBRATE THE WORK TOOL, THE OUTER END OF THE ACOUSTIC TRANSFORMER INCLUDES A THREADED TOP PORTION TO ENGAGE THE THREADS ON THE SHANK OF A WORK TOOL WHICH IS THREADABLY ADVANCED OR WITHDRAWN ON MANIPULATION OF THE CHUCK ON RAPID ASSEMBLY AND DISASSEMBLY OF WORK TOOLS FROM THE DENTAL INSTRUMENT.

June 29, 1971 B, RlCHMAN TI? FOR ULTRASONIG DENTAL INSTRUMENT 2 Sheets-Sheet l Filed June 30, 1969 MEI-Invii. N

June 29, 1971 B, RlCHMAN 3589,@2

TIP FOR ULTRASONIC DENTAL INSTRUMENT Filed June 50, 1969 2 Sheets-Sheet /Ajl/E/V TOE'. BRUCE R/CHMAN United States Patent O 3,589,012 TIP FOR ULTRASQNIC DENTAL INSTRUMENT Bruce Richman, North Miami Beach, Fla., assigner to C & B Corporation, North Miami Beach, Fla. Filed .lune 30, 1969, Ser. No. 837,581 Int. Cl. A61c 3/10 U.S. Cl. 32-58 14 Claims ABSTRACT F THE DISCLOSURE An ultrasonic dental instrument with a chuck for quickly attaching and detaching a work tool which chuck requires the use of no special tools. A conventional magnetostrictive acoustic transformer is included in the dental instrument to vibrate the work tool; the outer end of the acoustic transformer includes a threaded tip portion to engage the threads on the shank of a work tool which is threadably advanced or withdrawn on manipulation of the chuck on rapid assembly and disassembly of Work tools from the dental instrument.

This invention pertains to a dental tool and more particularly to an ultrasonic dental tool which employs an electric coil to supply vibrating energy to a magnetostrictive member and an acoustic transformer whereby on energization of the coil a work tool attached to the working end of the rod is caused to vibrate. To dissipate heat a uid path through the tool from a cooling water jacket attached to a supply source is provided.

-In the past, dental tools of the type described have required special tools for the removal from or replacement of work tools to the working end of the transformer, i.e. to the end of a member in a vibration transmitting system; and the general assembly of the component parts thereof was such that it has been difficult to assemble and disassemble the same for repairs or for replacement of the parts, as well as for interchanging the various types of work tools required and normally expected to be used in dental operations.

One of the principal objects of the present invention, therefore, is to provide a chuck as a manipulative part of a dental instrument which provides for very rapid insertion into and removal of a selected work tool from the instrument without the use of a separate or special wrenches or the like. This provides the extremely desirable effect of permitting a dentist or dental technician to change a work tool as often as necessary or preferred during the course of his or her work and in a minimum amount of time and with the elimination of the job elements of selecting a tool for use in changing the work tool, applying it to the instrument and discarding it.

Another object of this invention is to provide a dental instrument having internal screw threads in the outer tip end of the acoustic transformer which are adapted to receive mating external threads on the shank portion of a work tool in combination with a chuck on the instrument to advance or withdraw the work tool.

Yet another object of the instant invention is to provide an improved chuck means, rotatable about a threaded outer working end of a member connected in a vibration transmitting chain which is adapted for driving connection with threads on a work tool, whereby rotational movement of the chuck threadably advances or withdraws the work tool.

Still another object of the invention is to provide in such a combination of a dental instrument and a chuck at the working end, an improved mounting means for the chuck composed of mating land and annular groove means whereby the chuck means can be forceably inserted on or removed from a normal position in the working end of the ice dental instrument for rotational manipulation in attaching and detaching work tools thereto without axial displacement of the chuck.

Another object of the present invention is the simplified construction of the various components of the dental instrument described whereby the entire instrument may be assembled and disassembled to permit repairs or replacement of parts in a relatively short period of time and without the requirement of special tools.

Still another object of the invention is the provision of a fluid path opening in a member in the vibratory chain of an acoustic transformer type dental instrument whereby uid may be caused to ow in an axial direction to the elements of the vibratory chain and to a point of impingement upon a work tool in such a manner as to deliver a spray of cooling water to the distal end of the work portion of the work tool.

Other objects and advantages of the present invention will become more fully apparent from the following detailed description when read in conjunction with the accompanying drawings in which:

FIG. 1 is an elevational view o-f the dental tool of the present invention;

FIG. 2 is a longitudinal sectional view taken along the line 2 2 of FIG. l;

FIG. 3 is an enlarged fragmentary sectional view of the left portion of FIG. 2;

FIG. 4 is a cross sectional View taken along the line 4 4 of FIG. 3;

FIG. 5 is a cross sectional View taken along the line 5 5 of FIG. 3;

FIG. 6 is a cross sectional veiw taken along the line 6 6 of FIG. 3;

FIG. 7 is an exploded sectional view illustrating the manner in which the various elements with the exception of the chuck and work tool of FIG. 3 are assembled;

FIG. 8 is an exploded sectional view illustrating the manner in which the chuck and tool means are assembled after the elements illustrated in FIG. 7 are assembled.

Referring to the drawings in which like reference characters designate like or similar parts throughout the various views, the numeral 10 indicates the dental instrument or dental tool of the instant invention which is comprised generally of a housing 12, a sleeve 14 press fitted into coaxial relation in the housing, a rod member 16 in coaxial relation within the sleeve, a chuck 18 on the end of the instrument, and a work tool 20 threadably connected on the end of the rod and projecting outwardly through the chuck end of the dental instrument, and adapted to be threadably moved axially on manipulation of the chuck.

The housing 12 is generally tubular in form providing a longitudinal chamber 22, extending from the Working end 23, that is the distal or forward end of the instrument, to a reduced diameter through opening 24 in the proximal, supply or rear end 25 which provides a passage for electrical conductors 26 and 28 and, also, a Water supply 30 in a manner to be described hereinafter.

With reference to FIGS. 2 and 3, it is seen that the sleeve means 14 includes external centering flanges 32 and 34, for snug receipt within the chamber 22 which maintain the rod 16 in co-axial relation within the housing. Also, it is seen that the sleeve means 14 is provided with an enlarged extruding diametrical portion 36 at its front or distal end, which is sized to be press fitted into the lfront end 23 of the housing 22 with the cylindrical surface of this enlarged portion cooperating with the centering flanges 32 and 34 to maintain a co-axial relationship between the sleeve 14 and the housing 12. In other words the flanges and the enlarged portion act as positioning means to maintain the sleeve means and housing in coaxial relation. From the drawings it is seen that between these flanges and the enlarged portion a longitudinal annular pocket 318 is formed between the surface of the sleeve 14 and the surface 42 of the housing 12. A coil 44 is housed within this pocket 3'8, the coil being oircumposed about the sleeve 14 and connected to the conductors 26 and 28 at the proximal end of the instrument as illustrated in FIG. 2.

As best seen in FIGS. 3, 7 and 8, the distal end of the sleeve projects from the opening at the end of the housing and is of a diameter such as to be flush with the surface of the housing thereby defining a terminal enlarged end portion 48 and providing a shoulder 50 which normally lies in abutting relation with the front face 52 of the housing 12 when the sleeve is press fitted into the housing in the manner described. A longitudinal chamber 54 extends through the main length of the sleeve 14 and a reduced diameter through opening 56 is provided from the rear end of the chamber 54 for the reception of a nipple 58 which serves as a connector for the @fluid supply to 30 whereby a flow of coolant, such as water, through the tube enters the chamber 54.

The rod member 16, which is part of a vibration transmission system or chain, is seen in FIG. 2. It includes an elongate magnetostrictive member 60 and a collector or impedance transformer 62 connected at the distal end thereof, which terminates in a tip portion `68 which is axially bored and screw threaded as at 69 for the reception of a screw threaded shank portion 70 of a work tool 20. A pair of O-rings 64 and 65 are provided as a sealing means on the end of the transformer to constrain water or coolant to flow through a water passageway 71 which is provided through the connector 66 in communication between the chamber 54 and a screw threaded tip bore 69.

With particular reference to FIGS. 3 and 6, means indicated -generally at 72 are provided between the collector portion of the rod 16 and sleeve 14 to key these two elements together and to prevent rotation of the rod relative to the sleeve 14. In the embodiment illustrated, the enlarged front end portion 48 of the sleeve is internally screw threaded as at 74 for the reception of an externally screw threaded key element or insert having an internal bore 78 sized for cooperative sealing relation about the aforesaid `O-ring 64 when the rod 14 is in the normal position in the chamber 54, thus constraining passage of water from the chamber 54 through the passageway 71 and not generally from the distal end of the instrument. The bore 78 is stepped, that is a reduced diameter through opening 80 is provided rearwardly of the bore 78 and the side walls define a pair of opposite internal flats 81 and 82 which are loosely complementary to a pair of external flats '83 and 84 on the collector portion 85 of the rod rearwardly of the O-ring 64. The shoulder 86 defined by the stepped bore on the reduced diameter openingl 80 which is engaged by a flange 87 on the collector 66 to limit inward movement thereof and constituting axial location means for the rod, the O-ring 64 being seated in the annular groove 88 just forwardly of the shoulder 86 in the preferred embodiment. The loosely complementary relationship between the internal flats 81 and 82 and th external flats 83 and 84 provides a flow through passageway 89 for water flowing from the chamber 54 to a transverse mouth portion 90 of the water passageway 71 in the collector `66.

A screw threaded cap plug 92 is threaded into the screw threaded bore 74 against the working end face 94 of the insert 76 to provide stop means for a limited range of captivated longitudinal movement of the rod 18 between the position illustrated in FIGS. 2 and 3 and a position in which the O-rin-g 65 is engaged against the inner face 95 of the plug 92. A cross slot 96 is provided in the end face of the plug 92 for the reception of an appropriate tool for threaded advancement on insertion or withdrawal on removal thereof.

As best illustrated in FIGS. 3 and 8, the main body portion 98 of the chuck 18 is preferably substantially of an outer diameter equal to that of the sleeve portion 48 and housing 12 and is knurled as at 100, FIG. 1. A reduced diameter male proximal portion 102, as illustrated in FIGS. l, 3 and 8, is provided with a pair of axially spaced lands 104 and 106 which are adapted to be snapped into a pair of similarly spaced internal, annular grooves 108 and 110 in the forward end of the sleeve portion 48, the dimensions of the interengaging portions of the chuck 18 and sleeve portion 48 being such that free rotational movement of the chuck is provided relative to the sleeve portion when thus assembled.

In the embodiment illustrated, the chuck means 18 is provided with a through axial bore 111 including a distal or front portion 112 and an increased diameter rear portion 114, the front portion 112 being provided with a pair of diametrically opposed slots 116 and 118 extending along the length thereof for the reception of a pair of complementary projections 120 and 122 provided on the shaft 124 of the work tool 20.

As best illustrated in FIGS. 2 and 4, the above described structure provides a transmission means for irnparting rotational movement of the chuck 18 to advance or withdraw the work tool 20. When the work tool 28 is inserted in the chuck bore 111 in the manner indicated by the arrows in FIG. 8, and the tool 10 is slanted upwardly, the forces of gravity seat the screw threaded shank 70 of the work tool in the outwardly flared mouth 132 of the internally screw threaded tip portion 69 and, thereafter, subsequent rotation of the chuck 18 in the proper direction drives the shank 70 into tight engagement within the screw threaded tip 69. It is apparent that the: work tool thus attached to the dental instrument may be readily removed by reversing the direction of rotation of the chuck 18.

The work tool 20 includes a longitudinal uid passageway 134 in communication with the passageway 71 as illustrated in FIG. 3 whereby fluid flows from the supply tube 30 through the chamber 54, through the passageways 71 and 134 and is discharged through outlet post 136 adjacent the tip portion 138 of the work tool 20.

As is well known in the art, an energizing current to the coil 44 will cause the work tool holder and attached work tool to vibrate as the electrical energy is converted into mechanical energy by reason of the O-ring suspension of the transformer collector 62, and the vibratory motion is transmitted to the distal end 138 of the Work tool, a spray of water being provided to impinge on the extreme terminal end of the tool 20 during operation, in the manner above described.

While a preferred form of the invention has been illustrated and described, the key means 72 between the rod 16 and the sleeve 14 as well as the rotation transmission means between the chuck 18 and the work tool 20, could, in both instances, alternatively be accomplished in a num- Iber of ways, within this disclosure, for example, by the use of transverse pins or various complementary configurations whereby relative movement of one member to the other is constrained, i.e. the rod 16 relative to the sleeve 14 or the chuck 18 relative to the tool 20.

The exploded view, FIG. 7, illustrates the manner in which various elements of the tool 10 are assembled or disassembled for replacement of parts or repairs. In assembly, the electric conductors 26 and 28 and fluid supply tube 30 are inserted through the aperture 24 in the proximal end of the instrument and connected to the coil 44 and sleeve 14 as described, the sleeve is then press fitted into the housing 12 as indicated by the arrows 140 until the shoulder 50 abuts the annular face 52 of the housing 12. Next, the insert 76 is inserted into the screw threaded sleeve bore 74 as indicated by arrow 142 and the rod 16 is pushed through the opening 80 in the insert and is used as a tool to drive the insert 76 to the position illustrated in FIG. 3 and by the arrows 144, FIG. 7, by reason of the keying effect of the respective flats 81,

82 and 83, 84 thereon. The rod is then manually forced inwardly until the O-ring is in sealing engagement within the bore 78 and the cap plug 92 is driven into abutting engagement within the annular face 94 of the insert to captivate the rod and to limit it to a predetermined amount of longitudinal movement relative to sleeve 14, rotational movement being prevented by the key means as previously described.

With reference to FIG. 8, the chuck 18 is pressed or snapped into the forward end opening of the sleeve portion 48, as indicated by the arrows 146, the lands 104 and 106 becoming loosely engaged in the annular slots 108 and 110 to permit rotational movement of the chuck 18 relative to the sleeve. This completes assembly of the instrument and power must be employed to disassemble it, by forcing the chuck free of the working end by an axial force of an amount not to be encountered in ordinary use, and, thereafter, unscrewing the cap plug and key element, etc. Access to the interior may thus be had so that any necessary repairs can be made or parts replaced with a minimal amount of effort or time consumed.

In use, any of several in a selection of work tools may then be inserted into the chuck and rotated into fixed engagement on the rod tip as described. The above described procedure is reversed in changing tools; that is to say, the work tool may be replaced in a very short period of time without removal of any of the structural members of the assembled instrument simply by manipulating the chuck.

What is claimed is:

1. An ultrasonic dental instrument comprising:

a work tool holder including sleeve means having a distal working end and a proximal supply end to be connected to an energy source;

a rod coeaxially disposed within said sleeve means and having an outer end terminating adjacent said working end;

key means to key said rod against rotation in said sleeve means;

a work tool;

mutually interengaging means on said work tool and on said outer end to rotatably connect said work tool to said rod in a generally co-axial relationship and being of the type to be engaged or disengaged by rotation of said work tool relative to said outer end;

chuck means rotatable on the working end of the instrument for manipulating said mutually interengaging means to attach or detach the work tool to said outer end;

said chuck means including (a) means to engage said work tool and (b) mounting means to axially, but rotatably, fix said chuck means to the instrument to be carried thereby at all times in use.

2. An ultrasonic dental instrument as set forth in claim 1 wherein said work tool includes a shaft having a pattern in relief on the surface,

said mutually interengaging means includes mating threads on the shaft and said rod outer end, and

said means to engage said work tool on said chuck means comprises loosely mating means on said chuck means to mate with said pattern in relief,

whereby on rotational movement of said chuck means, torque is transmitted to the work tool to rotate said work tool relative to said outer end and to move it axially.

3. An ultrasonic dental instrument as set forth in claim 2 wherein said mounting means comprises,

loosely complementary sized land and groove means on said chuck means and said sleeve means, said land and groove means being adapted to be snapped into and out of interconnecting relationship on the application of axially directed forces, but permitting relative rotational movement of the chuck means and said sleeve means.

4. An ultrasonic dental instrument as set forth in claim 2 wherein said chuck means includes an axial through bore, and,

said loosely mating means comprises longitudinal and radially extending slot means in the wall of said Athrough bore, and,

said pattern in relief includes longitudinal and radially extending means on said work tool shaft sized and arranged for relative slidable axial movement longitudinally within said slot means to permit free longitudinal movement of said shaft in said bore and into engagement with said rod outer end.

5. An ultrasonic dental instrument as set forth in claim 4 wherein said mutually interengaging means comprises a threaded recess in the outer end of said rod and external screw threads on the proximal end of said shaft.

6. An ultrasonic dental instrument as set forth in claim 5 in which said slot means comprises a pair of diametrically opposed slots and said longitudinal and radially eX- tending means on said work tool are in diametrical relation.

7. An ultrasonic dental instrument as set forth in claim 1 wherein said work tool holder includes an outer tubular housing circumposed about said sleeve means and in coaxial relation therewith, said sleeve means including an enlarged working end portion extending outwardly of one end of said housing.

8. The instrument of claim 7 including spacer means intermediate said sleeve and housing and maintaining said sleeve means and said housing in said co-axial relation and defining an elongate annular pocket, said spacer means being sized for a snug co-axial positioning of said sleeve means within said housing.

9. An ultrasonic dental instrument as set forth in claim 8 including a coil in said annular pocket in circumposed relation about said sleeve means; said rod including a magnetostrictive portion in said sleeve means and a distal acoustic transformer portion including said mutually interengaging means on said outer end, said coil being adapted to be energized to vibrate said work tool; and resilient means intermediate said acoustic transformer and said sleeve means at the distal end effective to hold the rod in co-axial relation within said sleeve means as it vibrates.

10. The ultrasonic dental instrument as set forth in claim 9 wherein said resilient means includes an annular groove on the exterior of said acoustic transformer portion and a first O-ring in the groove, said first `O-ring being sized to resiliently nest between the rod and said sleeve means. 11. An ultrasonic dental instrument as set forth in claim 10 wherein said enlarged working end portion is internally screw threaded and an externally screw threaded insert is provided therein, said insert having an axial through bore with a reduced diameter proximal portion, said key means comprising loosely complementary ats on the exterior of said acoustic transformer and on the interior of said reduced diameter portion proximally of said first O-ring, whereby said rod is keyed against rotation in said sleeve means, and on rotation of said rod it acts as a tool for inserting or extracting said insert, said first O-ring being positioned in said through bore, and a screw threaded cap plug in said internal screw threads in abutment with said insert to captivate said rod and to limit longitudinal movement thereof as determined by the length of said insert bore, a second O-ring on said acoustic transformer distally of said first O-ring engaging said cap plug; said cap plug having a recess in the axial face thereof sized for engaging a tool for insertion or removal thereof.

12. An ultrasonic dental instrument as set forth in claim 9 including a fluid supply tube connected into the supply end of said pocket and fluid path defining means intermediate an open mouth in said rod outer end and said pocket.

13. An ultrasonic dental tool as set forth in claim 12 in which said fluid path defining means comprises the interior of said sleeve means, a bore in said acoustic transformer, having a radial branch from the surface of said acoustic transformer rearwardly of said O-ring, and an interior and a longitudinal branch in said transformer extending forwardly of said `O-ring and terminating at said open mouth of said rod.

14. An ultrasonic dental tool as set forth in claim 12 wherein said work tool includes a fluid path extending References Cited UNITED STATES PATENTS 5/1964 Seggern 32-26 1/1970 Haydu 32-58 ROBERT PESH'O'CK, Primary Examiner 

